“Dam Hetch Hetchy! As well dam for water tanks the people’s cathedrals and churches, for no holier temple has ever been consecrated by the heart of man! —John Muir

Hetch Hetchy Valley The floor of Hetch Hetchy Valley as it appeared in 1919, before the construction of O’Shaughnessy Dam was breathtaking. Note the tracks of the Hetch Hetchy Railroad. Before the dam could be built, access and transportation to the valley floor had to be established. Begun in 1914, the 68-mile railway was completed in 1917. Fed by a perpetual underground glacier, Hetch Hetchy offered a single source of water for the City of San Francisco.

AFTER

O'Shaughnessy Dam under construction, and Hetch Hetchy Reservoir_______________________________________________________________
This aerial shows the construction progress of the dam that many claim 'broke John Muir's heart'.

The initial 30 foot depth of the foundation for O’Shagunessy Dam increased to over 100 feet due to the dislodging of large boulders from the ancient glacier beneath the Valley floor. Two Cyclopean concrete blocks of stone measuring from one cubic foot to six cubic yards imbedded in plain concrete create the arch-style dam that counter-balances the pressure of the water. Physical construction of O’Shaugnessy Dam began in 1919 and was completed in 1923. Preparations, however, began as early as 1914 with construction of the Hetch Hetchy Railroad, a 68 mile standard gauge railway completed in 1917 for $3 million. The railroad operated around the clock during four years of construction, hauling cement, supplies and men. Clearing of timber from the Valley floor began in 1915, removing 21 million board feet by 1924. When completed, O’Shaugnessy Dam stood 226.5 feet high from the Valley floor with a storage capacity of 206,000 acre feet of water.

The first Hetch Hetchy drinking water arrived in San Francisco on October 28, 1934, two decades after initial construction began. In 1938, the dam was raised 85.5 feet enabling it to impound 360,000 acre feet of water. The total cost for the Dam, including the subsequent enlargement was $12.6 million. Fed by a perpetual glacier deep in the Sierra range, Hetch Hetchy water is the purest source of drinking water in the state of California. Today, the Alameda County Water District purchases nearly 40% of the county’s water from Hetch Hetchy.

On display as part of an exhibit on water rights on the 2nd floor of 2500 Mowry Street, Fremont, Washington Hospital, and published in rhe book Washington Township published by the Washington Hospital Medical Foundation

1 comment:

It is not correct that Hetch Hetchy is "Fed by a perpetual glacier deep in the Sierra range". It is fed by the Tuolumne River. Hetch Hetchy Reservoir is a storage facility where an iconic glacier carved valley used to be.

The reservoir should be moved outside Yosemite so the valley can be returned to the American people.

See the recent Fresno Bee column to learn more http://www.fresnobee.com/2014/07/09/4017819/the-elephant-in-yosemite-parkthe.html

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San Francisco born designer, historian, and photographer, developing 'green' production company that integrates exhibits, artwork and visual communication with your facilities.

Working with enterprise, government, health care, hospitality and entertainment clients since 1980.

Using eco-friendly methods, decoration is used for strategic communication to inspire and influence the experience of your audience, making the built environment fun, educational and fully integrated with your marketing plan and human factors objectives. Service includes program development, content development, production services, printing, 'sustainable' framing and exhibit production; integrated print and electronic media, archive management